{"gene":"CHEK2","run_date":"2026-06-09T22:57:18","timeline":{"discoveries":[{"year":1998,"finding":"CHEK2 (Chk2) is the mammalian homolog of yeast Rad53/Cds1 and is phosphorylated and activated in response to DNA damage in an ATM-dependent manner; in vitro, Chk2 phosphorylates Cdc25C on serine-216, a site involved in negative regulation of Cdc25C, implicating Chk2 in preventing mitotic entry after DNA damage.","method":"In vitro kinase assay, co-immunoprecipitation, cell-based phosphorylation assay","journal":"Science","confidence":"High","confidence_rationale":"Tier 1 / Strong — in vitro kinase assay demonstrating Cdc25C phosphorylation, ATM-dependency established in cells, foundational study replicated across multiple subsequent labs","pmids":["9836640"],"is_preprint":false},{"year":2000,"finding":"Chk2 directly phosphorylates p53 on serine-20, which interferes with Mdm2 binding and promotes p53 stabilization; Chk2-deficient mouse cells fail to stabilize p53 or induce p53-dependent transcripts (p21) after gamma-irradiation, and reintroduction of Chk2 restores p53-dependent transcription.","method":"Gene targeting (knockout mouse), in vitro kinase assay, transcriptional reporter assay, gamma-irradiation","journal":"Science","confidence":"High","confidence_rationale":"Tier 1 / Strong — genetic knockout combined with in vitro kinase assay, replicated by independent labs","pmids":["10710310"],"is_preprint":false},{"year":2001,"finding":"Chk2 phosphorylates Cdc25A on serine-123 downstream of ATM in response to ionizing radiation, triggering Cdc25A destruction, preventing Cdk2 dephosphorylation, and blocking DNA replication (S-phase checkpoint); tumor-associated Chk2 alleles cannot bind or phosphorylate Cdc25A.","method":"In vitro kinase assay, phosphorylation site mutagenesis, cell-based degradation assay, IR treatment","journal":"Nature","confidence":"High","confidence_rationale":"Tier 1 / Strong — in vitro kinase assay with mutagenesis, functional cell-based readout, independent replication","pmids":["11298456"],"is_preprint":false},{"year":2002,"finding":"Chk2-deficient mice show resistance to IR-induced apoptosis in thymocytes and neurons; the IR-induced G1/S checkpoint is impaired in Chk2-/- embryonic fibroblasts, while G2/M and S-phase checkpoints are less affected; p53 stabilization is partially reduced, and p53-dependent transcription of p21 and Noxa is abolished in Chk2-/- cells.","method":"Gene targeting (knockout mouse), flow cytometry, immunoblot, qRT-PCR","journal":"The EMBO journal","confidence":"High","confidence_rationale":"Tier 2 / Strong — genetic knockout with multiple orthogonal readouts, independent validation of Chk2 role in p53 pathway","pmids":["12356735"],"is_preprint":false},{"year":2002,"finding":"Chk2 undergoes ATM-dependent phosphorylation-dependent oligomerization after DNA damage; oligomerization requires the FHA domain of one Chk2 molecule to interact with the SQ/TQ cluster domain (SCD) of another; oligomers allow trans-autophosphorylation and kinase activation, and induced oligomerization alone augments Chk2 kinase activity.","method":"Cell-free system kinase assay, co-immunoprecipitation, mutagenesis, oligomerization/size exclusion analysis, chimeric Chk2 dimerization construct","journal":"Molecular and cellular biology","confidence":"High","confidence_rationale":"Tier 1 / Moderate — cell-free reconstitution with mutagenesis and multiple orthogonal methods, single lab","pmids":["12024051"],"is_preprint":false},{"year":2003,"finding":"ATM phosphorylates Chk2 at Thr68, promoting oligomerization and subsequent autophosphorylation of the activation loop at Thr383 and Thr387; Ser516 is an additional IR-inducible autophosphorylation site; the Li-Fraumeni mutation I157T impairs Chk2 oligomerization and autophosphorylation.","method":"In vitro kinase assay, in vivo phosphorylation with mutant cell lines, phospho-specific antibodies, mutagenesis","journal":"Molecular cancer research","confidence":"High","confidence_rationale":"Tier 1 / Moderate — in vitro and in vivo phosphorylation with mutagenesis, multiple phosphorylation sites mapped, single lab with orthogonal methods","pmids":["12805407"],"is_preprint":false},{"year":2009,"finding":"Crystal structure of dimeric CHK2 reveals that productive dimerization involves intermolecular phosphoThr68-FHA interactions, FHA-kinase domain interactions, and FHA-FHA interactions; in the dimer, kinase active sites face each other for efficient activation-loop transphosphorylation; Ile157, mutated in Li-Fraumeni syndrome, is central to the FHA-kinase domain interface and its mutation abolishes dimerization and autophosphorylation.","method":"X-ray crystallography, biochemical mutagenesis, kinase activity assays","journal":"Molecular cell","confidence":"High","confidence_rationale":"Tier 1 / Strong — crystal structure with functional biochemical and mutational validation in a single rigorous study","pmids":["19782031"],"is_preprint":false},{"year":2005,"finding":"Chk2 phosphorylates MDMX on Ser342 and Ser367 in vivo, stimulating MDMX ubiquitination and degradation by MDM2 following DNA damage, contributing to p53 activation; ATM-dependent degradation of MDMX precedes p53 accumulation.","method":"Co-immunoprecipitation, mass spectrometry, phospho-specific antibodies, RNAi knockdown, ubiquitination assay","journal":"The EMBO journal","confidence":"High","confidence_rationale":"Tier 2 / Moderate — reciprocal IP, mass spectrometry-confirmed sites, RNAi, ubiquitination assay, multiple orthogonal methods single lab","pmids":["16163388"],"is_preprint":false},{"year":2006,"finding":"Chk2-mediated phosphorylation of MDMX on Ser367 promotes 14-3-3 binding, MDMX nuclear import via a cryptic nuclear localization signal, and subsequent MDM2-mediated MDMX degradation; mutation of MDMX Ser367 inhibits ubiquitination, degradation, and nuclear import; 14-3-3 and Chk2 cooperatively stimulate MDMX ubiquitination.","method":"Co-immunoprecipitation/co-purification, mutagenesis, immunofluorescence, ubiquitination assay, nuclear fractionation","journal":"The EMBO journal","confidence":"High","confidence_rationale":"Tier 2 / Moderate — multiple orthogonal methods (co-IP, mutagenesis, localization, ubiquitination), single lab","pmids":["16511560"],"is_preprint":false},{"year":2003,"finding":"Karyopherin-alpha2 (KPNA-2) interacts with Chk2 through the Chk2 NLS-3 motif (amino acids 515-522); this interaction is required for Chk2 nuclear import, as mutations in NLS-3 (but not NLS-1 or NLS-2) cause cytoplasmic relocalization of Chk2.","method":"Yeast two-hybrid, GST pulldown, co-immunoprecipitation, mutagenesis, fluorescence microscopy","journal":"The Journal of biological chemistry","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — yeast two-hybrid confirmed by GST pulldown and co-IP, localization validated by mutagenesis, single lab","pmids":["12909615"],"is_preprint":false},{"year":2002,"finding":"Chk2 co-localizes with and co-immunoprecipitates Polo-like kinase 1 (Plk1); Plk1 overexpression enhances Chk2 phosphorylation at Thr68; Plk1 phosphorylates recombinant Chk2 in vitro; Chk2 phosphorylated at Thr68 and Thr26/Ser28 is present at centrosomes and midbodies in the absence of DNA damage.","method":"Co-immunoprecipitation, in vitro kinase assay, indirect immunofluorescence","journal":"The Journal of biological chemistry","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — co-IP plus in vitro kinase assay plus localization, single lab","pmids":["12493754"],"is_preprint":false},{"year":2005,"finding":"DNA-dependent protein kinase (DNA-PK) can phosphorylate Chk2 at Thr68 in vitro; endogenous Chk2 co-immunoprecipitates Ku70 and Ku80; in cells lacking functional DNA-PKcs, IR-induced Chk2 phosphorylation is consistently diminished; DNA-PK augments ATM and ATR in activating Chk2 after DNA damage.","method":"In vitro kinase assay with purified DNA-PK, co-immunoprecipitation, siRNA knockdown, matched cell lines with/without functional DNA-PK","journal":"The Journal of biological chemistry","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — in vitro kinase assay with purified protein, co-IP, and functional cell-based validation, single lab","pmids":["15668230"],"is_preprint":false},{"year":2000,"finding":"Tumor-associated Chk2 FHA domain mutations: R145W retains basal kinase activity but cannot be phosphorylated at ATM-dependent Thr68 and cannot be activated by gamma-irradiation, and forms a larger aberrant complex in cells; wild-type Chk2 exists in a complex of ~200 kDa. Another FHA mutation I157T behaves similarly to wild-type in all biochemical assays tested.","method":"In vitro kinase assay, immunoprecipitation, gel filtration, gamma-irradiation","journal":"The Journal of biological chemistry","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — multiple biochemical methods, characterization of specific disease mutants, single lab","pmids":["11053450"],"is_preprint":false},{"year":2004,"finding":"Chk2 is required for replicative senescence in human fibroblasts: Chk2 is phosphorylated and activated at short dysfunctional telomeres; inactivation of Chk2 reduces p21(waf1) expression and extends proliferative lifespan, consistent with failure to activate p53.","method":"Immunofluorescence, immunoblot, siRNA knockdown, proliferation assay","journal":"The EMBO journal","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — siRNA knockdown with functional proliferation and molecular readouts, single lab","pmids":["15192702"],"is_preprint":false},{"year":2006,"finding":"EDD (human orthologue of Drosophila hyperplastic discs) associates with CHK2 through a phospho-dependent interaction involving the CHK2 FHA domain and EDD threonine residues; RNAi depletion of EDD impairs CHK2 activating phosphorylation and kinase activity in response to IR, identifying EDD as a mediator upstream of CHK2.","method":"Co-immunoprecipitation, RNAi knockdown, in vitro kinase assay, IR treatment","journal":"The Journal of biological chemistry","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — co-IP plus RNAi functional validation plus kinase assay, single lab","pmids":["17074762"],"is_preprint":false},{"year":2008,"finding":"TRAIL-induced apoptosis activates Chk2 phosphorylation downstream of the mitochondrial death pathway; Chk2 phosphorylation is dependent on both ATM and DNA-PK; downregulation of Chk2 delays activation of caspases 2, 3, 8, and 9 and reduces TRAIL-induced cell killing, indicating Chk2 acts as a positive feedback amplifier of the apoptotic response.","method":"Immunofluorescence, siRNA knockdown, caspase activity assay, co-localization microscopy","journal":"Molecular and cellular biology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — siRNA knockdown with functional caspase readouts and inhibitor validation, single lab","pmids":["18955500"],"is_preprint":false},{"year":2007,"finding":"ATR (not ATM or DNA-PK) is the critical upstream activator of Chk2 in cisplatin-induced apoptosis in renal cells; both Chk1 and Chk2 are phosphorylated in an ATR-dependent manner; Chk2 inhibition (dominant-negative or gene deficiency) attenuates cisplatin-induced p53 activation and apoptosis; in vivo, ATR and Chk2 are activated in renal tissues after cisplatin treatment.","method":"Dominant-negative mutant expression, ATR-deficient fibroblasts, siRNA, immunofluorescence, in vivo mouse model","journal":"The Journal of biological chemistry","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — multiple genetic tools (dominant-negative, knockout cells, siRNA) with mechanistic readouts, single lab","pmids":["18162465"],"is_preprint":false},{"year":2019,"finding":"SIRT1 directly interacts with CHK2, deacetylates CHK2 at lysine 520, which suppresses CHK2 phosphorylation, dimerization, and activation; SIRT1 depletion induces CHK2 hyperactivation-mediated cell cycle arrest and cell death; genetic deletion of Chk2 rescues neonatal lethality of Sirt1-/- mice.","method":"Co-immunoprecipitation, deacetylation assay, mutagenesis, mouse genetic epistasis (Sirt1-/-;Chk2-/- double knockout)","journal":"Cell death and differentiation","confidence":"High","confidence_rationale":"Tier 1 / Moderate — biochemical reconstitution of deacetylation, mutagenesis, and in vivo genetic epistasis in single study","pmids":["31209362"],"is_preprint":false},{"year":2019,"finding":"USP39 deubiquitinates and stabilizes CHK2 protein; USP39 knockdown reduces CHK2 levels and compromises DNA damage-induced G2/M checkpoint activation, apoptosis, and sensitizes cells to chemotherapy and radiation.","method":"shRNA knockdown, ubiquitination assay, immunoblot, flow cytometry (G2/M checkpoint), cell survival assay","journal":"Cancer letters","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — deubiquitination assay plus functional knockdown with multiple readouts, single lab","pmids":["30771428"],"is_preprint":false},{"year":2020,"finding":"CHK2 binds to and phosphorylates Beclin 1 at Ser90/Ser93, impairing Beclin 1-Bcl-2 complex formation in a ROS-dependent fashion and thereby promoting autophagy; CHK2-/- mice show aggravated infarct phenotypes and reduced Beclin 1 phosphorylation in a cerebral stroke model.","method":"Co-immunoprecipitation, in vitro kinase assay with mutagenesis, Chk2 knockout mice, cerebral stroke in vivo model","journal":"The EMBO journal","confidence":"High","confidence_rationale":"Tier 1 / Moderate — in vitro kinase assay with mutagenesis, co-IP, and in vivo genetic validation, single lab with multiple orthogonal methods","pmids":["32187724"],"is_preprint":false},{"year":2020,"finding":"CHK2 phosphorylates FOXK1 and FOXK2, creating a 14-3-3γ binding site that traps FOXK proteins in the cytoplasm, thereby de-repressing ATG gene transcription and promoting autophagy in response to DNA damage.","method":"Co-immunoprecipitation, in vitro kinase assay, subcellular fractionation, reporter assay, mutagenesis","journal":"Science advances","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — co-IP plus in vitro kinase assay plus localization with functional transcriptional readout, single lab","pmids":["31911943"],"is_preprint":false},{"year":2014,"finding":"Chk2 phosphorylates REGγ on Ser247, increasing REGγ-DBC1 interaction, which in turn inhibits SIRT1 and promotes p53 acetylation and apoptosis in response to DNA damage; Chk2 inactivation reduces DBC1-SIRT1 binding and prevents p53 acetylation.","method":"Co-immunoprecipitation, in vitro kinase assay, siRNA knockdown, acetylation assay","journal":"Nucleic acids research","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — co-IP plus in vitro kinase assay plus siRNA functional validation, single lab","pmids":["25361978"],"is_preprint":false},{"year":2008,"finding":"Chk2 deficiency does not modify checkpoint defects or chromosomal instability of Mre11 complex mutants, but Nbs1-/Chk2- and Mre11-/Chk2- double mutant mice show synergistic defects in DNA-damage-induced p53 regulation and apoptosis and are predisposed to tumors; Chk2 specifically suppresses oncogenic potential of DNA damage arising during S and G2 phases.","method":"Compound knockout mouse genetics, epistasis analysis, tumor incidence, apoptosis assays","journal":"Molecular cell","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — genetic epistasis with double knockout mice and multiple phenotypic readouts, single lab","pmids":["18614044"],"is_preprint":false},{"year":2001,"finding":"Chk2 protein is stable, nuclear, and activatable throughout the cell cycle including in quiescent and differentiating cells; in human tissues, Chk2 expression is homogeneous in renewing cell populations, heterogeneous in conditionally renewing tissues, and absent or cytoplasmic in static tissues such as muscle or brain.","method":"Immunohistochemistry, immunofluorescence, subcellular fractionation, Western blot across cell cycle phases","journal":"Cancer research","confidence":"Medium","confidence_rationale":"Tier 3 / Moderate — direct localization experiments across multiple tissue types, multiple methods, single lab","pmids":["11431331"],"is_preprint":false},{"year":2003,"finding":"A truncated CHK2 protein encoded by a novel 1368insA mutation is stable yet mislocalizes to the cytoplasm both in tumor sections and when ectopically expressed in cultured cells, indicating that cytoplasmic sequestration is a mechanism to disable CHK2 function.","method":"Ectopic expression, immunofluorescence/immunohistochemistry in tumor sections","journal":"Oncogene","confidence":"Low","confidence_rationale":"Tier 3 / Weak — single lab, localization assay without full mechanistic follow-up of the sequestration mechanism","pmids":["15361853"],"is_preprint":false},{"year":2014,"finding":"DNA-PKcs is the upstream regulator of Chk2 phosphorylation at Thr68 during mitosis; Chk2 activates BRCA1, which promotes monoubiquitination of γ-tubulin to inhibit microtubule nucleation; loss of DNA-PKcs results in chromosome misalignment rescued by phosphomimetic Chk2 or BRCA1.","method":"siRNA knockdown, phosphomimetic mutant rescue, immunofluorescence, co-immunoprecipitation","journal":"Oncogenesis","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — epistasis via knockdown and phosphomimetic rescue, multiple readouts, single lab","pmids":["24492479"],"is_preprint":false},{"year":2015,"finding":"CRAF pSer338 recruits CHK2 and promotes CHK2 phosphorylation/activation to enhance the DNA damage response and tumor radioresistance; a phospho-mimetic CRAF S338D mutant is sufficient to induce CRAF/CHK2 association.","method":"Co-immunoprecipitation, phosphorylation assay, phospho-mimetic mutant, allosteric inhibitor","journal":"Nature communications","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — co-IP with phospho-mimetic mutant and functional radioresistance readout, single lab","pmids":["26333361"],"is_preprint":false},{"year":2005,"finding":"Chk2-dependent induction of p21(Waf1/Cip1) and senescence can occur in p53-defective cells; siRNA-mediated knockdown of p21 in p53-defective cells expressing Chk2 reduces senescence, establishing a p53-independent pathway for Chk2-driven senescence.","method":"Viral transduction of Chk2, siRNA knockdown of p21, senescence assays in p53-defective cell lines","journal":"Molecular cancer research","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — siRNA epistasis in multiple p53-defective cell lines with functional senescence readout, single lab","pmids":["16317088"],"is_preprint":false},{"year":2020,"finding":"CHK2 is required for elimination of oocytes with unrepaired meiotic DSBs; both CHK1 and CHK2 become activated by persistent DSBs in oocytes; oocytes lacking both p53 and TAp63 are nearly fully protected from elimination, placing CHK1/CHK2 upstream of TRP53/TAp63 in a semiredundant oocyte elimination pathway.","method":"Genetic epistasis with knockout mice (Chk2-/-, p53-/-, TAp63-/-, Spo11-/-, Trip13-/-), histological analysis","journal":"Genetics","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — compound knockout genetic epistasis with multiple allele combinations, single lab","pmids":["32273296"],"is_preprint":false},{"year":2021,"finding":"CHK2 controls expression of succinate dehydrogenase (SDH) and intervenes with mitochondrial functions; DNA damage and CHK2 promote SDH activity and increased succinate oxidation through the TCA cycle; cells with DNA damage and elevated CHK2 rely on glycolysis for ATP production due to dysfunctional mitochondria; CHK2 knockdown abolishes this metabolic shift.","method":"siRNA knockdown, metabolic profiling (NMR), mitochondrial function assays, transgenic HCC mouse model","journal":"Cancer research","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — siRNA knockdown with metabolic and functional readouts, in vivo transgenic validation, single lab","pmids":["33762357"],"is_preprint":false}],"current_model":"CHEK2 encodes a serine/threonine kinase that is activated downstream of ATM (and to a lesser extent ATR and DNA-PK) via phosphorylation at Thr68, which drives transient dimerization through FHA-domain interactions, activation-loop autophosphorylation at Thr383/387, and subsequent phosphorylation of multiple substrates including Cdc25A (Ser123), Cdc25C (Ser216), p53 (Ser20), MDMX (Ser342/Ser367), BRCA1, Beclin 1 (Ser90/93), FOXK1/2, and REGγ (Ser247) to coordinate cell cycle arrest, apoptosis, DNA repair, autophagy, and senescence; its activity is negatively regulated by SIRT1-mediated deacetylation at Lys520 and positively by deubiquitination through USP39, while nuclear import depends on karyopherin-alpha2 binding to the NLS-3 motif."},"narrative":{"mechanistic_narrative":"CHEK2 encodes a DNA-damage-activated serine/threonine checkpoint kinase, the mammalian homolog of yeast Rad53/Cds1, that is phosphorylated and activated downstream of ATM in response to genotoxic stress to coordinate cell cycle arrest, apoptosis, and senescence [PMID:9836640]. Activation proceeds through ATM-mediated phosphorylation of Thr68, which drives FHA-domain-dependent oligomerization and trans-autophosphorylation of the activation-loop residues Thr383/Thr387; crystallographic analysis shows that productive dimerization is built from intermolecular phospho-Thr68–FHA, FHA–kinase, and FHA–FHA contacts that orient the two kinase active sites for transphosphorylation, and the Li-Fraumeni mutation Ile157 sits at the FHA–kinase interface where its mutation abolishes dimerization and activation [PMID:12024051, PMID:12805407, PMID:19782031]. Once active, CHEK2 enforces checkpoints by phosphorylating Cdc25C on Ser216 and Cdc25A on Ser123, the latter triggering Cdc25A destruction to block CDK2 and DNA replication [PMID:9836640, PMID:11298456]. CHEK2 is a principal activating kinase of the p53 axis: it phosphorylates p53 on Ser20 to disrupt Mdm2 binding and phosphorylates MDMX on Ser342/Ser367 to promote its 14-3-3 binding, nuclear import, and MDM2-mediated degradation, with Chk2-deficient cells failing to induce p53-dependent transcripts such as p21 and Noxa and resisting IR-induced apoptosis [PMID:10710310, PMID:12356735, PMID:16163388, PMID:16511560]. Beyond classical checkpoint control, CHEK2 promotes autophagy by phosphorylating Beclin 1 (Ser90/Ser93) to disrupt the Beclin1-Bcl-2 complex and by phosphorylating FOXK1/FOXK2 to sequester them in the cytoplasm and de-repress ATG genes [PMID:32187724, PMID:31911943], and it drives replicative and p53-independent senescence through p21 induction at dysfunctional telomeres [PMID:15192702, PMID:16317088]. CHEK2 activity is tuned by post-translational regulation—SIRT1 deacetylates Lys520 to suppress its dimerization and activation, while USP39 deubiquitinates and stabilizes the protein—and its nuclear import depends on karyopherin-alpha2 binding the NLS-3 motif [PMID:31209362, PMID:30771428, PMID:12909615]. Genetically, CHEK2 suppresses tumorigenesis arising from S/G2-phase DNA damage [PMID:18614044].","teleology":[{"year":1998,"claim":"Established CHEK2 as the mammalian DNA-damage checkpoint kinase, answering how cells translate ATM signaling into a block on mitotic entry.","evidence":"In vitro kinase assay and cell-based phosphorylation showing ATM-dependent activation and Cdc25C Ser216 phosphorylation","pmids":["9836640"],"confidence":"High","gaps":["Did not establish the full substrate repertoire","Mechanism of kinase activation not resolved"]},{"year":2000,"claim":"Connected CHEK2 to the p53 tumor-suppressor axis, defining how checkpoint kinase activity stabilizes p53 after damage.","evidence":"Knockout mouse cells, in vitro kinase assay, and transcriptional reporter showing p53 Ser20 phosphorylation and p21 induction","pmids":["10710310"],"confidence":"High","gaps":["Did not quantify the relative contribution of Chk2 versus other p53 kinases","p53-independent functions not addressed"]},{"year":2001,"claim":"Defined the S-phase checkpoint mechanism by which CHEK2 halts replication, and linked tumor-associated alleles to substrate-binding failure.","evidence":"In vitro kinase assay with site mutagenesis and cell-based Cdc25A degradation after IR","pmids":["11298456"],"confidence":"High","gaps":["In vivo contribution of the Cdc25A arm to tumor suppression not isolated"]},{"year":2002,"claim":"Resolved the activation mechanism, showing FHA-domain-driven oligomerization enables trans-autophosphorylation and kinase activation.","evidence":"Cell-free kinase assays, co-IP, mutagenesis, and chimeric dimerization constructs","pmids":["12024051"],"confidence":"High","gaps":["Atomic geometry of the dimer not yet defined","Kinetics of oligomer assembly unresolved"]},{"year":2002,"claim":"Genetically separated which checkpoints and apoptotic programs depend on Chk2 in the intact animal.","evidence":"Knockout mice with flow cytometry, immunoblot, and qRT-PCR readouts after IR","pmids":["12356735"],"confidence":"High","gaps":["Partial p53 stabilization implies redundant kinases not identified here"]},{"year":2003,"claim":"Mapped the activation phosphorylation cascade (Thr68 then activation-loop Thr383/387) and tied a Li-Fraumeni mutation to defective activation.","evidence":"In vitro and in vivo phosphorylation with phospho-specific antibodies and I157T mutant analysis","pmids":["12805407"],"confidence":"High","gaps":["Functional consequence of Ser516 autophosphorylation not fully defined"]},{"year":2003,"claim":"Identified the nuclear import mechanism, showing karyopherin-alpha2 recognizes the NLS-3 motif to localize CHEK2 to the nucleus.","evidence":"Yeast two-hybrid, GST pulldown, co-IP, and NLS mutagenesis with microscopy","pmids":["12909615"],"confidence":"Medium","gaps":["Regulation of import in response to damage not addressed","Single-lab interaction not reciprocally validated in vivo"]},{"year":2005,"claim":"Extended CHEK2's p53-activating role to MDMX, showing it triggers MDMX degradation upstream of p53 accumulation.","evidence":"Co-IP, mass spectrometry site mapping, RNAi, and ubiquitination assays for Ser342/Ser367","pmids":["16163388","16511560"],"confidence":"High","gaps":["Quantitative contribution of MDMX degradation relative to direct p53 phosphorylation unresolved"]},{"year":2009,"claim":"Provided the structural basis for FHA-mediated dimerization and explained why Ile157 mutation abolishes activation.","evidence":"X-ray crystallography of dimeric CHK2 with biochemical mutagenesis and kinase assays","pmids":["19782031"],"confidence":"High","gaps":["Structure does not capture the full-length damage-activated complex in cells"]},{"year":2008,"claim":"Broadened upstream activation beyond ATM, implicating DNA-PK, ATR, and EDD as context-dependent activators of CHEK2.","evidence":"In vitro kinase assays with purified DNA-PK, DNA-PKcs/ATR-deficient cells, RNAi, and co-IP across separate studies","pmids":["15668230","18162465","17074762"],"confidence":"Medium","gaps":["Relative weighting of ATM/ATR/DNA-PK across damage types not unified","EDD mechanism of activation not mapped to specific phosphosites"]},{"year":2008,"claim":"Defined the tumor-suppressive niche of CHEK2 within the MRN-checkpoint network through genetic epistasis.","evidence":"Compound knockout mouse genetics with tumor incidence and apoptosis readouts","pmids":["18614044"],"confidence":"Medium","gaps":["Molecular basis of the S/G2-specific suppression not delineated"]},{"year":2019,"claim":"Revealed reciprocal post-translational control of CHEK2 abundance and activity via USP39 stabilization and SIRT1 deacetylation.","evidence":"Deubiquitination/deacetylation assays, mutagenesis, knockdown, and Sirt1/Chk2 double-knockout genetic epistasis","pmids":["30771428","31209362"],"confidence":"High","gaps":["Conditions selecting deacetylation versus deubiquitination not defined","Acetyltransferase opposing SIRT1 at Lys520 not identified"]},{"year":2020,"claim":"Established CHEK2 as a direct driver of autophagy through Beclin 1 and FOXK1/2 phosphorylation, extending its role beyond cell cycle control.","evidence":"In vitro kinase assays with mutagenesis, co-IP, fractionation, reporter assays, and Chk2-knockout stroke model","pmids":["32187724","31911943"],"confidence":"Medium","gaps":["Integration of autophagic and checkpoint outputs in the same cell unresolved","FOXK arm validated in single lab"]},{"year":2021,"claim":"Linked CHEK2 to metabolic reprogramming, showing it modulates succinate dehydrogenase and a glycolytic shift after DNA damage.","evidence":"siRNA knockdown with NMR metabolic profiling, mitochondrial assays, and a transgenic HCC mouse model","pmids":["33762357"],"confidence":"Medium","gaps":["Direct substrate mediating SDH control not identified","Single-lab metabolic mechanism"]},{"year":null,"claim":"How CHEK2 partitions its activated pool among checkpoint, apoptotic, autophagic, senescence, and metabolic outputs in a given cell remains unresolved.","evidence":"","pmids":[],"confidence":"Medium","gaps":["No quantitative model of substrate selection downstream of activation","Determinants of upstream kinase (ATM/ATR/DNA-PK) choice not unified","Coordination of nuclear versus centrosomal/mitochondrial functions unclear"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0140096","term_label":"catalytic activity, acting on a protein","supporting_discovery_ids":[0,1,2,7,19,20,21]},{"term_id":"GO:0016740","term_label":"transferase activity","supporting_discovery_ids":[0,2,5,6]},{"term_id":"GO:0140657","term_label":"ATP-dependent activity","supporting_discovery_ids":[0,4]}],"localization":[{"term_id":"GO:0005634","term_label":"nucleus","supporting_discovery_ids":[9,23]},{"term_id":"GO:0005815","term_label":"microtubule organizing center","supporting_discovery_ids":[10]},{"term_id":"GO:0005829","term_label":"cytosol","supporting_discovery_ids":[24]}],"pathway":[{"term_id":"R-HSA-73894","term_label":"DNA Repair","supporting_discovery_ids":[0,2,5]},{"term_id":"R-HSA-1640170","term_label":"Cell Cycle","supporting_discovery_ids":[0,2,3]},{"term_id":"R-HSA-5357801","term_label":"Programmed Cell Death","supporting_discovery_ids":[3,15,28]},{"term_id":"R-HSA-9612973","term_label":"Autophagy","supporting_discovery_ids":[19,20]},{"term_id":"R-HSA-8953897","term_label":"Cellular responses to stimuli","supporting_discovery_ids":[13,27]}],"complexes":[],"partners":["TP53","CDC25A","CDC25C","MDM4","BECN1","KPNA2","SIRT1","USP39"],"other_free_text":[]}},"prefetch_data":{"uniprot":{"accession":"O96017","full_name":"Serine/threonine-protein kinase Chk2","aliases":["CHK2 checkpoint homolog","Cds1 homolog","Hucds1","hCds1","Checkpoint kinase 2"],"length_aa":543,"mass_kda":60.9,"function":"Serine/threonine-protein kinase which is required for checkpoint-mediated cell cycle arrest, activation of DNA repair and apoptosis in response to the presence of DNA double-strand breaks. May also negatively regulate cell cycle progression during unperturbed cell cycles. Following activation, phosphorylates numerous effectors preferentially at the consensus sequence [L-X-R-X-X-S/T] (PubMed:37943659). Regulates cell cycle checkpoint arrest through phosphorylation of CDC25A, CDC25B and CDC25C, inhibiting their activity. Inhibition of CDC25 phosphatase activity leads to increased inhibitory tyrosine phosphorylation of CDK-cyclin complexes and blocks cell cycle progression. May also phosphorylate NEK6 which is involved in G2/M cell cycle arrest. Regulates DNA repair through phosphorylation of BRCA2, enhancing the association of RAD51 with chromatin which promotes DNA repair by homologous recombination. Also stimulates the transcription of genes involved in DNA repair (including BRCA2) through the phosphorylation and activation of the transcription factor FOXM1. Regulates apoptosis through the phosphorylation of p53/TP53, MDM4 and PML. Phosphorylation of p53/TP53 at 'Ser-20' by CHEK2 may alleviate inhibition by MDM2, leading to accumulation of active p53/TP53. Phosphorylation of MDM4 may also reduce degradation of p53/TP53. Also controls the transcription of pro-apoptotic genes through phosphorylation of the transcription factor E2F1. Tumor suppressor, it may also have a DNA damage-independent function in mitotic spindle assembly by phosphorylating BRCA1. Its absence may be a cause of the chromosomal instability observed in some cancer cells. Promotes the CCAR2-SIRT1 association and is required for CCAR2-mediated SIRT1 inhibition (PubMed:25361978). Under oxidative stress, promotes ATG7 ubiquitination by phosphorylating the E3 ubiquitin ligase TRIM32 at 'Ser-55' leading to positive regulation of the autophagosme assembly (PubMed:37943659) (Microbial infection) Phosphorylates herpes simplex virus 1/HHV-1 protein ICP0 and thus activates its SUMO-targeted ubiquitin ligase activity","subcellular_location":"Nucleus, PML body; Nucleus, nucleoplasm","url":"https://www.uniprot.org/uniprotkb/O96017/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":false,"resolved_as":"","url":"https://depmap.org/portal/gene/CHEK2","classification":"Not 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cancer","url":"https://pubmed.ncbi.nlm.nih.gov/35643632","citation_count":39,"is_preprint":false},{"pmid":"28360097","id":"PMC_28360097","title":"CHK2 overexpression and mislocalisation within mitotic structures enhances chromosomal instability and hepatocellular carcinoma progression.","date":"2017","source":"Gut","url":"https://pubmed.ncbi.nlm.nih.gov/28360097","citation_count":39,"is_preprint":false},{"pmid":"19457865","id":"PMC_19457865","title":"Reconstitution of Rad53 activation by Mec1 through adaptor protein Mrc1.","date":"2009","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/19457865","citation_count":39,"is_preprint":false},{"pmid":"26553136","id":"PMC_26553136","title":"Genomic profiling of CHEK2*1100delC-mutated breast carcinomas.","date":"2015","source":"BMC cancer","url":"https://pubmed.ncbi.nlm.nih.gov/26553136","citation_count":38,"is_preprint":false},{"pmid":"11793476","id":"PMC_11793476","title":"A robust method for detecting CHK2/RAD53 mutations in genomic DNA.","date":"2002","source":"Human mutation","url":"https://pubmed.ncbi.nlm.nih.gov/11793476","citation_count":37,"is_preprint":false},{"pmid":"30907073","id":"PMC_30907073","title":"SALL4 induces radioresistance in nasopharyngeal carcinoma via the ATM/Chk2/p53 pathway.","date":"2019","source":"Cancer medicine","url":"https://pubmed.ncbi.nlm.nih.gov/30907073","citation_count":37,"is_preprint":false},{"pmid":"19876921","id":"PMC_19876921","title":"CHEK2 mutations and HNPCC-related colorectal cancer.","date":"2010","source":"International journal of cancer","url":"https://pubmed.ncbi.nlm.nih.gov/19876921","citation_count":36,"is_preprint":false},{"pmid":"16365046","id":"PMC_16365046","title":"Activation of the checkpoint kinase Rad53 by the phosphatidyl inositol kinase-like kinase Mec1.","date":"2005","source":"The Journal of biological 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cell","url":"https://pubmed.ncbi.nlm.nih.gov/30595439","citation_count":28,"is_preprint":false}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":43814,"output_tokens":7129,"usd":0.119189,"stage1_stop_reason":"end_turn"},"stage2":{"model":"claude-opus-4-8","input_tokens":16212,"output_tokens":4405,"usd":0.095592,"stage2_stop_reason":"end_turn"},"total_usd":0.214781,"stage1_batch_id":"msgbatch_01ACAxJQabDsht39JXeWG22d","stage2_batch_id":"msgbatch_01QEU22A9U5sbPTgsMzTmvSf","note":"batch pricing = 50% of standard"},"stage1_raw":"```json\n{\n  \"discoveries\": [\n    {\n      \"year\": 1998,\n      \"finding\": \"CHEK2 (Chk2) is the mammalian homolog of yeast Rad53/Cds1 and is phosphorylated and activated in response to DNA damage in an ATM-dependent manner; in vitro, Chk2 phosphorylates Cdc25C on serine-216, a site involved in negative regulation of Cdc25C, implicating Chk2 in preventing mitotic entry after DNA damage.\",\n      \"method\": \"In vitro kinase assay, co-immunoprecipitation, cell-based phosphorylation assay\",\n      \"journal\": \"Science\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Strong — in vitro kinase assay demonstrating Cdc25C phosphorylation, ATM-dependency established in cells, foundational study replicated across multiple subsequent labs\",\n      \"pmids\": [\"9836640\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2000,\n      \"finding\": \"Chk2 directly phosphorylates p53 on serine-20, which interferes with Mdm2 binding and promotes p53 stabilization; Chk2-deficient mouse cells fail to stabilize p53 or induce p53-dependent transcripts (p21) after gamma-irradiation, and reintroduction of Chk2 restores p53-dependent transcription.\",\n      \"method\": \"Gene targeting (knockout mouse), in vitro kinase assay, transcriptional reporter assay, gamma-irradiation\",\n      \"journal\": \"Science\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Strong — genetic knockout combined with in vitro kinase assay, replicated by independent labs\",\n      \"pmids\": [\"10710310\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2001,\n      \"finding\": \"Chk2 phosphorylates Cdc25A on serine-123 downstream of ATM in response to ionizing radiation, triggering Cdc25A destruction, preventing Cdk2 dephosphorylation, and blocking DNA replication (S-phase checkpoint); tumor-associated Chk2 alleles cannot bind or phosphorylate Cdc25A.\",\n      \"method\": \"In vitro kinase assay, phosphorylation site mutagenesis, cell-based degradation assay, IR treatment\",\n      \"journal\": \"Nature\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Strong — in vitro kinase assay with mutagenesis, functional cell-based readout, independent replication\",\n      \"pmids\": [\"11298456\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2002,\n      \"finding\": \"Chk2-deficient mice show resistance to IR-induced apoptosis in thymocytes and neurons; the IR-induced G1/S checkpoint is impaired in Chk2-/- embryonic fibroblasts, while G2/M and S-phase checkpoints are less affected; p53 stabilization is partially reduced, and p53-dependent transcription of p21 and Noxa is abolished in Chk2-/- cells.\",\n      \"method\": \"Gene targeting (knockout mouse), flow cytometry, immunoblot, qRT-PCR\",\n      \"journal\": \"The EMBO journal\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — genetic knockout with multiple orthogonal readouts, independent validation of Chk2 role in p53 pathway\",\n      \"pmids\": [\"12356735\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2002,\n      \"finding\": \"Chk2 undergoes ATM-dependent phosphorylation-dependent oligomerization after DNA damage; oligomerization requires the FHA domain of one Chk2 molecule to interact with the SQ/TQ cluster domain (SCD) of another; oligomers allow trans-autophosphorylation and kinase activation, and induced oligomerization alone augments Chk2 kinase activity.\",\n      \"method\": \"Cell-free system kinase assay, co-immunoprecipitation, mutagenesis, oligomerization/size exclusion analysis, chimeric Chk2 dimerization construct\",\n      \"journal\": \"Molecular and cellular biology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Moderate — cell-free reconstitution with mutagenesis and multiple orthogonal methods, single lab\",\n      \"pmids\": [\"12024051\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2003,\n      \"finding\": \"ATM phosphorylates Chk2 at Thr68, promoting oligomerization and subsequent autophosphorylation of the activation loop at Thr383 and Thr387; Ser516 is an additional IR-inducible autophosphorylation site; the Li-Fraumeni mutation I157T impairs Chk2 oligomerization and autophosphorylation.\",\n      \"method\": \"In vitro kinase assay, in vivo phosphorylation with mutant cell lines, phospho-specific antibodies, mutagenesis\",\n      \"journal\": \"Molecular cancer research\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Moderate — in vitro and in vivo phosphorylation with mutagenesis, multiple phosphorylation sites mapped, single lab with orthogonal methods\",\n      \"pmids\": [\"12805407\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2009,\n      \"finding\": \"Crystal structure of dimeric CHK2 reveals that productive dimerization involves intermolecular phosphoThr68-FHA interactions, FHA-kinase domain interactions, and FHA-FHA interactions; in the dimer, kinase active sites face each other for efficient activation-loop transphosphorylation; Ile157, mutated in Li-Fraumeni syndrome, is central to the FHA-kinase domain interface and its mutation abolishes dimerization and autophosphorylation.\",\n      \"method\": \"X-ray crystallography, biochemical mutagenesis, kinase activity assays\",\n      \"journal\": \"Molecular cell\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Strong — crystal structure with functional biochemical and mutational validation in a single rigorous study\",\n      \"pmids\": [\"19782031\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2005,\n      \"finding\": \"Chk2 phosphorylates MDMX on Ser342 and Ser367 in vivo, stimulating MDMX ubiquitination and degradation by MDM2 following DNA damage, contributing to p53 activation; ATM-dependent degradation of MDMX precedes p53 accumulation.\",\n      \"method\": \"Co-immunoprecipitation, mass spectrometry, phospho-specific antibodies, RNAi knockdown, ubiquitination assay\",\n      \"journal\": \"The EMBO journal\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — reciprocal IP, mass spectrometry-confirmed sites, RNAi, ubiquitination assay, multiple orthogonal methods single lab\",\n      \"pmids\": [\"16163388\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2006,\n      \"finding\": \"Chk2-mediated phosphorylation of MDMX on Ser367 promotes 14-3-3 binding, MDMX nuclear import via a cryptic nuclear localization signal, and subsequent MDM2-mediated MDMX degradation; mutation of MDMX Ser367 inhibits ubiquitination, degradation, and nuclear import; 14-3-3 and Chk2 cooperatively stimulate MDMX ubiquitination.\",\n      \"method\": \"Co-immunoprecipitation/co-purification, mutagenesis, immunofluorescence, ubiquitination assay, nuclear fractionation\",\n      \"journal\": \"The EMBO journal\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — multiple orthogonal methods (co-IP, mutagenesis, localization, ubiquitination), single lab\",\n      \"pmids\": [\"16511560\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2003,\n      \"finding\": \"Karyopherin-alpha2 (KPNA-2) interacts with Chk2 through the Chk2 NLS-3 motif (amino acids 515-522); this interaction is required for Chk2 nuclear import, as mutations in NLS-3 (but not NLS-1 or NLS-2) cause cytoplasmic relocalization of Chk2.\",\n      \"method\": \"Yeast two-hybrid, GST pulldown, co-immunoprecipitation, mutagenesis, fluorescence microscopy\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — yeast two-hybrid confirmed by GST pulldown and co-IP, localization validated by mutagenesis, single lab\",\n      \"pmids\": [\"12909615\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2002,\n      \"finding\": \"Chk2 co-localizes with and co-immunoprecipitates Polo-like kinase 1 (Plk1); Plk1 overexpression enhances Chk2 phosphorylation at Thr68; Plk1 phosphorylates recombinant Chk2 in vitro; Chk2 phosphorylated at Thr68 and Thr26/Ser28 is present at centrosomes and midbodies in the absence of DNA damage.\",\n      \"method\": \"Co-immunoprecipitation, in vitro kinase assay, indirect immunofluorescence\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — co-IP plus in vitro kinase assay plus localization, single lab\",\n      \"pmids\": [\"12493754\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2005,\n      \"finding\": \"DNA-dependent protein kinase (DNA-PK) can phosphorylate Chk2 at Thr68 in vitro; endogenous Chk2 co-immunoprecipitates Ku70 and Ku80; in cells lacking functional DNA-PKcs, IR-induced Chk2 phosphorylation is consistently diminished; DNA-PK augments ATM and ATR in activating Chk2 after DNA damage.\",\n      \"method\": \"In vitro kinase assay with purified DNA-PK, co-immunoprecipitation, siRNA knockdown, matched cell lines with/without functional DNA-PK\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — in vitro kinase assay with purified protein, co-IP, and functional cell-based validation, single lab\",\n      \"pmids\": [\"15668230\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2000,\n      \"finding\": \"Tumor-associated Chk2 FHA domain mutations: R145W retains basal kinase activity but cannot be phosphorylated at ATM-dependent Thr68 and cannot be activated by gamma-irradiation, and forms a larger aberrant complex in cells; wild-type Chk2 exists in a complex of ~200 kDa. Another FHA mutation I157T behaves similarly to wild-type in all biochemical assays tested.\",\n      \"method\": \"In vitro kinase assay, immunoprecipitation, gel filtration, gamma-irradiation\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — multiple biochemical methods, characterization of specific disease mutants, single lab\",\n      \"pmids\": [\"11053450\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2004,\n      \"finding\": \"Chk2 is required for replicative senescence in human fibroblasts: Chk2 is phosphorylated and activated at short dysfunctional telomeres; inactivation of Chk2 reduces p21(waf1) expression and extends proliferative lifespan, consistent with failure to activate p53.\",\n      \"method\": \"Immunofluorescence, immunoblot, siRNA knockdown, proliferation assay\",\n      \"journal\": \"The EMBO journal\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — siRNA knockdown with functional proliferation and molecular readouts, single lab\",\n      \"pmids\": [\"15192702\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2006,\n      \"finding\": \"EDD (human orthologue of Drosophila hyperplastic discs) associates with CHK2 through a phospho-dependent interaction involving the CHK2 FHA domain and EDD threonine residues; RNAi depletion of EDD impairs CHK2 activating phosphorylation and kinase activity in response to IR, identifying EDD as a mediator upstream of CHK2.\",\n      \"method\": \"Co-immunoprecipitation, RNAi knockdown, in vitro kinase assay, IR treatment\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — co-IP plus RNAi functional validation plus kinase assay, single lab\",\n      \"pmids\": [\"17074762\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2008,\n      \"finding\": \"TRAIL-induced apoptosis activates Chk2 phosphorylation downstream of the mitochondrial death pathway; Chk2 phosphorylation is dependent on both ATM and DNA-PK; downregulation of Chk2 delays activation of caspases 2, 3, 8, and 9 and reduces TRAIL-induced cell killing, indicating Chk2 acts as a positive feedback amplifier of the apoptotic response.\",\n      \"method\": \"Immunofluorescence, siRNA knockdown, caspase activity assay, co-localization microscopy\",\n      \"journal\": \"Molecular and cellular biology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — siRNA knockdown with functional caspase readouts and inhibitor validation, single lab\",\n      \"pmids\": [\"18955500\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2007,\n      \"finding\": \"ATR (not ATM or DNA-PK) is the critical upstream activator of Chk2 in cisplatin-induced apoptosis in renal cells; both Chk1 and Chk2 are phosphorylated in an ATR-dependent manner; Chk2 inhibition (dominant-negative or gene deficiency) attenuates cisplatin-induced p53 activation and apoptosis; in vivo, ATR and Chk2 are activated in renal tissues after cisplatin treatment.\",\n      \"method\": \"Dominant-negative mutant expression, ATR-deficient fibroblasts, siRNA, immunofluorescence, in vivo mouse model\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — multiple genetic tools (dominant-negative, knockout cells, siRNA) with mechanistic readouts, single lab\",\n      \"pmids\": [\"18162465\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2019,\n      \"finding\": \"SIRT1 directly interacts with CHK2, deacetylates CHK2 at lysine 520, which suppresses CHK2 phosphorylation, dimerization, and activation; SIRT1 depletion induces CHK2 hyperactivation-mediated cell cycle arrest and cell death; genetic deletion of Chk2 rescues neonatal lethality of Sirt1-/- mice.\",\n      \"method\": \"Co-immunoprecipitation, deacetylation assay, mutagenesis, mouse genetic epistasis (Sirt1-/-;Chk2-/- double knockout)\",\n      \"journal\": \"Cell death and differentiation\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Moderate — biochemical reconstitution of deacetylation, mutagenesis, and in vivo genetic epistasis in single study\",\n      \"pmids\": [\"31209362\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2019,\n      \"finding\": \"USP39 deubiquitinates and stabilizes CHK2 protein; USP39 knockdown reduces CHK2 levels and compromises DNA damage-induced G2/M checkpoint activation, apoptosis, and sensitizes cells to chemotherapy and radiation.\",\n      \"method\": \"shRNA knockdown, ubiquitination assay, immunoblot, flow cytometry (G2/M checkpoint), cell survival assay\",\n      \"journal\": \"Cancer letters\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — deubiquitination assay plus functional knockdown with multiple readouts, single lab\",\n      \"pmids\": [\"30771428\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2020,\n      \"finding\": \"CHK2 binds to and phosphorylates Beclin 1 at Ser90/Ser93, impairing Beclin 1-Bcl-2 complex formation in a ROS-dependent fashion and thereby promoting autophagy; CHK2-/- mice show aggravated infarct phenotypes and reduced Beclin 1 phosphorylation in a cerebral stroke model.\",\n      \"method\": \"Co-immunoprecipitation, in vitro kinase assay with mutagenesis, Chk2 knockout mice, cerebral stroke in vivo model\",\n      \"journal\": \"The EMBO journal\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Moderate — in vitro kinase assay with mutagenesis, co-IP, and in vivo genetic validation, single lab with multiple orthogonal methods\",\n      \"pmids\": [\"32187724\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2020,\n      \"finding\": \"CHK2 phosphorylates FOXK1 and FOXK2, creating a 14-3-3γ binding site that traps FOXK proteins in the cytoplasm, thereby de-repressing ATG gene transcription and promoting autophagy in response to DNA damage.\",\n      \"method\": \"Co-immunoprecipitation, in vitro kinase assay, subcellular fractionation, reporter assay, mutagenesis\",\n      \"journal\": \"Science advances\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — co-IP plus in vitro kinase assay plus localization with functional transcriptional readout, single lab\",\n      \"pmids\": [\"31911943\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2014,\n      \"finding\": \"Chk2 phosphorylates REGγ on Ser247, increasing REGγ-DBC1 interaction, which in turn inhibits SIRT1 and promotes p53 acetylation and apoptosis in response to DNA damage; Chk2 inactivation reduces DBC1-SIRT1 binding and prevents p53 acetylation.\",\n      \"method\": \"Co-immunoprecipitation, in vitro kinase assay, siRNA knockdown, acetylation assay\",\n      \"journal\": \"Nucleic acids research\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — co-IP plus in vitro kinase assay plus siRNA functional validation, single lab\",\n      \"pmids\": [\"25361978\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2008,\n      \"finding\": \"Chk2 deficiency does not modify checkpoint defects or chromosomal instability of Mre11 complex mutants, but Nbs1-/Chk2- and Mre11-/Chk2- double mutant mice show synergistic defects in DNA-damage-induced p53 regulation and apoptosis and are predisposed to tumors; Chk2 specifically suppresses oncogenic potential of DNA damage arising during S and G2 phases.\",\n      \"method\": \"Compound knockout mouse genetics, epistasis analysis, tumor incidence, apoptosis assays\",\n      \"journal\": \"Molecular cell\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — genetic epistasis with double knockout mice and multiple phenotypic readouts, single lab\",\n      \"pmids\": [\"18614044\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2001,\n      \"finding\": \"Chk2 protein is stable, nuclear, and activatable throughout the cell cycle including in quiescent and differentiating cells; in human tissues, Chk2 expression is homogeneous in renewing cell populations, heterogeneous in conditionally renewing tissues, and absent or cytoplasmic in static tissues such as muscle or brain.\",\n      \"method\": \"Immunohistochemistry, immunofluorescence, subcellular fractionation, Western blot across cell cycle phases\",\n      \"journal\": \"Cancer research\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 3 / Moderate — direct localization experiments across multiple tissue types, multiple methods, single lab\",\n      \"pmids\": [\"11431331\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2003,\n      \"finding\": \"A truncated CHK2 protein encoded by a novel 1368insA mutation is stable yet mislocalizes to the cytoplasm both in tumor sections and when ectopically expressed in cultured cells, indicating that cytoplasmic sequestration is a mechanism to disable CHK2 function.\",\n      \"method\": \"Ectopic expression, immunofluorescence/immunohistochemistry in tumor sections\",\n      \"journal\": \"Oncogene\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 3 / Weak — single lab, localization assay without full mechanistic follow-up of the sequestration mechanism\",\n      \"pmids\": [\"15361853\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2014,\n      \"finding\": \"DNA-PKcs is the upstream regulator of Chk2 phosphorylation at Thr68 during mitosis; Chk2 activates BRCA1, which promotes monoubiquitination of γ-tubulin to inhibit microtubule nucleation; loss of DNA-PKcs results in chromosome misalignment rescued by phosphomimetic Chk2 or BRCA1.\",\n      \"method\": \"siRNA knockdown, phosphomimetic mutant rescue, immunofluorescence, co-immunoprecipitation\",\n      \"journal\": \"Oncogenesis\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — epistasis via knockdown and phosphomimetic rescue, multiple readouts, single lab\",\n      \"pmids\": [\"24492479\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2015,\n      \"finding\": \"CRAF pSer338 recruits CHK2 and promotes CHK2 phosphorylation/activation to enhance the DNA damage response and tumor radioresistance; a phospho-mimetic CRAF S338D mutant is sufficient to induce CRAF/CHK2 association.\",\n      \"method\": \"Co-immunoprecipitation, phosphorylation assay, phospho-mimetic mutant, allosteric inhibitor\",\n      \"journal\": \"Nature communications\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — co-IP with phospho-mimetic mutant and functional radioresistance readout, single lab\",\n      \"pmids\": [\"26333361\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2005,\n      \"finding\": \"Chk2-dependent induction of p21(Waf1/Cip1) and senescence can occur in p53-defective cells; siRNA-mediated knockdown of p21 in p53-defective cells expressing Chk2 reduces senescence, establishing a p53-independent pathway for Chk2-driven senescence.\",\n      \"method\": \"Viral transduction of Chk2, siRNA knockdown of p21, senescence assays in p53-defective cell lines\",\n      \"journal\": \"Molecular cancer research\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — siRNA epistasis in multiple p53-defective cell lines with functional senescence readout, single lab\",\n      \"pmids\": [\"16317088\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2020,\n      \"finding\": \"CHK2 is required for elimination of oocytes with unrepaired meiotic DSBs; both CHK1 and CHK2 become activated by persistent DSBs in oocytes; oocytes lacking both p53 and TAp63 are nearly fully protected from elimination, placing CHK1/CHK2 upstream of TRP53/TAp63 in a semiredundant oocyte elimination pathway.\",\n      \"method\": \"Genetic epistasis with knockout mice (Chk2-/-, p53-/-, TAp63-/-, Spo11-/-, Trip13-/-), histological analysis\",\n      \"journal\": \"Genetics\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — compound knockout genetic epistasis with multiple allele combinations, single lab\",\n      \"pmids\": [\"32273296\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2021,\n      \"finding\": \"CHK2 controls expression of succinate dehydrogenase (SDH) and intervenes with mitochondrial functions; DNA damage and CHK2 promote SDH activity and increased succinate oxidation through the TCA cycle; cells with DNA damage and elevated CHK2 rely on glycolysis for ATP production due to dysfunctional mitochondria; CHK2 knockdown abolishes this metabolic shift.\",\n      \"method\": \"siRNA knockdown, metabolic profiling (NMR), mitochondrial function assays, transgenic HCC mouse model\",\n      \"journal\": \"Cancer research\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — siRNA knockdown with metabolic and functional readouts, in vivo transgenic validation, single lab\",\n      \"pmids\": [\"33762357\"],\n      \"is_preprint\": false\n    }\n  ],\n  \"current_model\": \"CHEK2 encodes a serine/threonine kinase that is activated downstream of ATM (and to a lesser extent ATR and DNA-PK) via phosphorylation at Thr68, which drives transient dimerization through FHA-domain interactions, activation-loop autophosphorylation at Thr383/387, and subsequent phosphorylation of multiple substrates including Cdc25A (Ser123), Cdc25C (Ser216), p53 (Ser20), MDMX (Ser342/Ser367), BRCA1, Beclin 1 (Ser90/93), FOXK1/2, and REGγ (Ser247) to coordinate cell cycle arrest, apoptosis, DNA repair, autophagy, and senescence; its activity is negatively regulated by SIRT1-mediated deacetylation at Lys520 and positively by deubiquitination through USP39, while nuclear import depends on karyopherin-alpha2 binding to the NLS-3 motif.\"\n}\n```","stage2_raw":"{\n  \"mechanistic_narrative\": \"CHEK2 encodes a DNA-damage-activated serine/threonine checkpoint kinase, the mammalian homolog of yeast Rad53/Cds1, that is phosphorylated and activated downstream of ATM in response to genotoxic stress to coordinate cell cycle arrest, apoptosis, and senescence [#0]. Activation proceeds through ATM-mediated phosphorylation of Thr68, which drives FHA-domain-dependent oligomerization and trans-autophosphorylation of the activation-loop residues Thr383/Thr387; crystallographic analysis shows that productive dimerization is built from intermolecular phospho-Thr68\\u2013FHA, FHA\\u2013kinase, and FHA\\u2013FHA contacts that orient the two kinase active sites for transphosphorylation, and the Li-Fraumeni mutation Ile157 sits at the FHA\\u2013kinase interface where its mutation abolishes dimerization and activation [#4, #5, #6]. Once active, CHEK2 enforces checkpoints by phosphorylating Cdc25C on Ser216 and Cdc25A on Ser123, the latter triggering Cdc25A destruction to block CDK2 and DNA replication [#0, #2]. CHEK2 is a principal activating kinase of the p53 axis: it phosphorylates p53 on Ser20 to disrupt Mdm2 binding and phosphorylates MDMX on Ser342/Ser367 to promote its 14-3-3 binding, nuclear import, and MDM2-mediated degradation, with Chk2-deficient cells failing to induce p53-dependent transcripts such as p21 and Noxa and resisting IR-induced apoptosis [#1, #3, #7, #8]. Beyond classical checkpoint control, CHEK2 promotes autophagy by phosphorylating Beclin 1 (Ser90/Ser93) to disrupt the Beclin1-Bcl-2 complex and by phosphorylating FOXK1/FOXK2 to sequester them in the cytoplasm and de-repress ATG genes [#19, #20], and it drives replicative and p53-independent senescence through p21 induction at dysfunctional telomeres [#13, #27]. CHEK2 activity is tuned by post-translational regulation\\u2014SIRT1 deacetylates Lys520 to suppress its dimerization and activation, while USP39 deubiquitinates and stabilizes the protein\\u2014and its nuclear import depends on karyopherin-alpha2 binding the NLS-3 motif [#17, #18, #9]. Genetically, CHEK2 suppresses tumorigenesis arising from S/G2-phase DNA damage [#22].\",\n  \"teleology\": [\n    {\n      \"year\": 1998,\n      \"claim\": \"Established CHEK2 as the mammalian DNA-damage checkpoint kinase, answering how cells translate ATM signaling into a block on mitotic entry.\",\n      \"evidence\": \"In vitro kinase assay and cell-based phosphorylation showing ATM-dependent activation and Cdc25C Ser216 phosphorylation\",\n      \"pmids\": [\"9836640\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Did not establish the full substrate repertoire\", \"Mechanism of kinase activation not resolved\"]\n    },\n    {\n      \"year\": 2000,\n      \"claim\": \"Connected CHEK2 to the p53 tumor-suppressor axis, defining how checkpoint kinase activity stabilizes p53 after damage.\",\n      \"evidence\": \"Knockout mouse cells, in vitro kinase assay, and transcriptional reporter showing p53 Ser20 phosphorylation and p21 induction\",\n      \"pmids\": [\"10710310\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Did not quantify the relative contribution of Chk2 versus other p53 kinases\", \"p53-independent functions not addressed\"]\n    },\n    {\n      \"year\": 2001,\n      \"claim\": \"Defined the S-phase checkpoint mechanism by which CHEK2 halts replication, and linked tumor-associated alleles to substrate-binding failure.\",\n      \"evidence\": \"In vitro kinase assay with site mutagenesis and cell-based Cdc25A degradation after IR\",\n      \"pmids\": [\"11298456\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"In vivo contribution of the Cdc25A arm to tumor suppression not isolated\"]\n    },\n    {\n      \"year\": 2002,\n      \"claim\": \"Resolved the activation mechanism, showing FHA-domain-driven oligomerization enables trans-autophosphorylation and kinase activation.\",\n      \"evidence\": \"Cell-free kinase assays, co-IP, mutagenesis, and chimeric dimerization constructs\",\n      \"pmids\": [\"12024051\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Atomic geometry of the dimer not yet defined\", \"Kinetics of oligomer assembly unresolved\"]\n    },\n    {\n      \"year\": 2002,\n      \"claim\": \"Genetically separated which checkpoints and apoptotic programs depend on Chk2 in the intact animal.\",\n      \"evidence\": \"Knockout mice with flow cytometry, immunoblot, and qRT-PCR readouts after IR\",\n      \"pmids\": [\"12356735\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Partial p53 stabilization implies redundant kinases not identified here\"]\n    },\n    {\n      \"year\": 2003,\n      \"claim\": \"Mapped the activation phosphorylation cascade (Thr68 then activation-loop Thr383/387) and tied a Li-Fraumeni mutation to defective activation.\",\n      \"evidence\": \"In vitro and in vivo phosphorylation with phospho-specific antibodies and I157T mutant analysis\",\n      \"pmids\": [\"12805407\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Functional consequence of Ser516 autophosphorylation not fully defined\"]\n    },\n    {\n      \"year\": 2003,\n      \"claim\": \"Identified the nuclear import mechanism, showing karyopherin-alpha2 recognizes the NLS-3 motif to localize CHEK2 to the nucleus.\",\n      \"evidence\": \"Yeast two-hybrid, GST pulldown, co-IP, and NLS mutagenesis with microscopy\",\n      \"pmids\": [\"12909615\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Regulation of import in response to damage not addressed\", \"Single-lab interaction not reciprocally validated in vivo\"]\n    },\n    {\n      \"year\": 2005,\n      \"claim\": \"Extended CHEK2's p53-activating role to MDMX, showing it triggers MDMX degradation upstream of p53 accumulation.\",\n      \"evidence\": \"Co-IP, mass spectrometry site mapping, RNAi, and ubiquitination assays for Ser342/Ser367\",\n      \"pmids\": [\"16163388\", \"16511560\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Quantitative contribution of MDMX degradation relative to direct p53 phosphorylation unresolved\"]\n    },\n    {\n      \"year\": 2009,\n      \"claim\": \"Provided the structural basis for FHA-mediated dimerization and explained why Ile157 mutation abolishes activation.\",\n      \"evidence\": \"X-ray crystallography of dimeric CHK2 with biochemical mutagenesis and kinase assays\",\n      \"pmids\": [\"19782031\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Structure does not capture the full-length damage-activated complex in cells\"]\n    },\n    {\n      \"year\": 2008,\n      \"claim\": \"Broadened upstream activation beyond ATM, implicating DNA-PK, ATR, and EDD as context-dependent activators of CHEK2.\",\n      \"evidence\": \"In vitro kinase assays with purified DNA-PK, DNA-PKcs/ATR-deficient cells, RNAi, and co-IP across separate studies\",\n      \"pmids\": [\"15668230\", \"18162465\", \"17074762\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Relative weighting of ATM/ATR/DNA-PK across damage types not unified\", \"EDD mechanism of activation not mapped to specific phosphosites\"]\n    },\n    {\n      \"year\": 2008,\n      \"claim\": \"Defined the tumor-suppressive niche of CHEK2 within the MRN-checkpoint network through genetic epistasis.\",\n      \"evidence\": \"Compound knockout mouse genetics with tumor incidence and apoptosis readouts\",\n      \"pmids\": [\"18614044\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Molecular basis of the S/G2-specific suppression not delineated\"]\n    },\n    {\n      \"year\": 2019,\n      \"claim\": \"Revealed reciprocal post-translational control of CHEK2 abundance and activity via USP39 stabilization and SIRT1 deacetylation.\",\n      \"evidence\": \"Deubiquitination/deacetylation assays, mutagenesis, knockdown, and Sirt1/Chk2 double-knockout genetic epistasis\",\n      \"pmids\": [\"30771428\", \"31209362\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Conditions selecting deacetylation versus deubiquitination not defined\", \"Acetyltransferase opposing SIRT1 at Lys520 not identified\"]\n    },\n    {\n      \"year\": 2020,\n      \"claim\": \"Established CHEK2 as a direct driver of autophagy through Beclin 1 and FOXK1/2 phosphorylation, extending its role beyond cell cycle control.\",\n      \"evidence\": \"In vitro kinase assays with mutagenesis, co-IP, fractionation, reporter assays, and Chk2-knockout stroke model\",\n      \"pmids\": [\"32187724\", \"31911943\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Integration of autophagic and checkpoint outputs in the same cell unresolved\", \"FOXK arm validated in single lab\"]\n    },\n    {\n      \"year\": 2021,\n      \"claim\": \"Linked CHEK2 to metabolic reprogramming, showing it modulates succinate dehydrogenase and a glycolytic shift after DNA damage.\",\n      \"evidence\": \"siRNA knockdown with NMR metabolic profiling, mitochondrial assays, and a transgenic HCC mouse model\",\n      \"pmids\": [\"33762357\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Direct substrate mediating SDH control not identified\", \"Single-lab metabolic mechanism\"]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"How CHEK2 partitions its activated pool among checkpoint, apoptotic, autophagic, senescence, and metabolic outputs in a given cell remains unresolved.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"No quantitative model of substrate selection downstream of activation\", \"Determinants of upstream kinase (ATM/ATR/DNA-PK) choice not unified\", \"Coordination of nuclear versus centrosomal/mitochondrial functions unclear\"]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0140096\", \"supporting_discovery_ids\": [0, 1, 2, 7, 19, 20, 21]},\n      {\"term_id\": \"GO:0016740\", \"supporting_discovery_ids\": [0, 2, 5, 6]},\n      {\"term_id\": \"GO:0140657\", \"supporting_discovery_ids\": [0, 4]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005634\", \"supporting_discovery_ids\": [9, 23]},\n      {\"term_id\": \"GO:0005815\", \"supporting_discovery_ids\": [10]},\n      {\"term_id\": \"GO:0005829\", \"supporting_discovery_ids\": [24]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-73894\", \"supporting_discovery_ids\": [0, 2, 5]},\n      {\"term_id\": \"R-HSA-1640170\", \"supporting_discovery_ids\": [0, 2, 3]},\n      {\"term_id\": \"R-HSA-5357801\", \"supporting_discovery_ids\": [3, 15, 28]},\n      {\"term_id\": \"R-HSA-9612973\", \"supporting_discovery_ids\": [19, 20]},\n      {\"term_id\": \"R-HSA-8953897\", \"supporting_discovery_ids\": [13, 27]}\n    ],\n    \"complexes\": [],\n    \"partners\": [\"TP53\", \"CDC25A\", \"CDC25C\", \"MDM4\", \"BECN1\", \"KPNA2\", \"SIRT1\", \"USP39\"],\n    \"other_free_text\": []\n  }\n}","audit_flag":null,"evaluation":{"pairwise":"win","faith_supported":7,"faith_total":7,"faith_pct":100.0}}